I no longer allow 'normal' crayons into my house having used these. They are excellent - exactly the same as other crayons in texture and usability but so easily cleaned if your child decides to decorate other unwanted places. With the help of a baby wipe I can clean any messes they make in seconds :o).
I however wouldn't personally describe them as big - more like middle sized. They are bigger than a standard crayon but smaller than the big fat ones you can get. I gave 4 stars for durabilty because they do break - but they are no worse than a standard crayon.